There are three main types of wireless network: wireless local area networks (WLAN), wireless personal area networks (WPAN) and wireless wide area networks (WWAN). A WWAN can have a range of up to 20 miles and offers users a way to access data while away from home, the office or public access facilities. A WWAN transmits data over a mobile phone network. A WPAN is implemented by wireless PAN devices communicating with each other over a wireless connection. Such devices typically have a range of up to 160 feet and may include Bluetooth™ devices such as mobile telephones, laptops and handheld devices. A WLAN has a range of up to 300 feet, and is commonly used in homes and offices and to provide general public access facilities.
A typical WLAN is implemented by using an access point to transmit data between the devices connected to the network. An access point is a radio communications device that connects wireless clients. A typical access point allows wireless clients to access a single wireless network. The access point function may be incorporated into a router. A router transfers packets between networks and can therefore be used to connect a wireless network to a wired network such as a local area network or the internet. Incorporating the access point function into a router therefore provides the advantages of enabling clients in a wireless network to access a number of other networks.
A wireless client may be any device that is capable of transmitting data over wireless connections. Commonly a wireless network may connect various computerized devices, such as workstations, laptop computers, printers, and PDAs, to name a few. A device need not be inherently a wireless device to be connected to a wireless network as wireless network adaptors can be connected to non-wireless devices (such as printers) to enable them to be connected to the network.
In a typical wireless network, a device has to demonstrate that it knows certain security information before it can communicate over the network. One commonly used piece of information is the service set identifier (SSID), which is the name of a particular wireless network. An SSID is typically a 32-bit, case sensitive code. Devices in a wireless network may be required to employ the appropriate SSID in order to communicate with each other over the network. Typically, the SSID is attached to all packets transmitted over the wireless network to identify each packet as part of the network. The SSID therefore functions to identify each packet and to uniquely identify a group of wireless network devices in a given service set.
As an additional security measure, devices may also be required to encrypt data using a private key. If a device does not know the private key, it cannot correctly encrypt and decrypt data and so is unable to communicate with other wireless devices over the network. A private key is typically a 63-bit code. Such codes are used, for example, in wireless networks that employ wireless encryption (WEP) or Wi-Fi Protected Access (WPA) for protection.
The SSID and any private key therefore need to be known by all devices that wish to communicate over the wireless network.
The SSID can be set manually by entering the SSID into each device or automatically by leaving the SSID unspecified. Some access points broadcast the SSID so that it is communicated to all wireless devices within range. This is not a preferred method of communicating the SSID for security reasons. Broadcasting the SSID makes it available to any rogue device within range of the broadcast. However, even if for security reasons the SSID is not broadcast by the access point it can still possible for rogue devices to obtain the SSID by “snooping”. For this reason, it can be advantageous to apply extra security, for example by utilizing a private key, so that even if a rogue device obtains the SSID it is not necessarily able to join the network.
Since the purpose of the private key is to improve security over a wireless network, it should not be broadcast freely to any devices within range. One option is to enter the key manually into all devices that are to form part of the wireless network. This has the disadvantage of being time consuming and potentially inaccurate. A private key can typically be up to 63 characters long and a user will commonly make mistakes while typing such a large number of characters into a device. The user also has to keep a record of the private key, which may be lost, making it impossible to connect new devices to the network using the original private key.